NASA's climate tracking satellite, Orbiting Carbon Observatory (OCO-2) revealed the five new studies on the climate change on Thursday, Space.com reported. Climate change occurs due to multiple human activities, such as deforestation or excessive use of fossil fuels.

OCO-2 was launched by NASA on July 20, 2014, after the failure of OCO during liftoff. It has been orbiting the Earth for three years, collecting data on the greenhouse gas emission and detecting the amount of carbon dioxide (CO2) absorbed by tropical forests on Earth which are responsible for the rise in global temperature.

OCO-2's observations

NASA scientists said that during the 2015-2016 El Nino, the largest emission of Greenhouse Gases happened, which was responsible for the greater rise in the amount of global CO2. A research team of OCO-2 analyzed the tropical regions of South America, Africa, and Indonesia, and found that they have stopped pulling the maximum amount of CO2 in the last few years.

A researcher at the Jet Propulsion Laboratory Junjie Liu said that "These three tropical regions released 2.5 gigatons more carbon into the atmosphere than they did in 2011," according to NASA. Scientists also pointed out that carbon emission has increased from 20% to 80% after 2011 El Nino.

Research by NASA scientists

The project scientist of OCO-2, Annmarie Eldering said that the tropical regions of the Earth are responsible for the largest annual increase in CO2 in past 2000 years, Space.com reported. Earlier this year, the Trump administration has cut the budget for NASA's five missions related to Earth science and climate change. So, NASA published 5 studies to show the importance of the OCO-2 mission.

Eldering also said that oceans and plants consume half of the carbon dioxide for photosynthesis, and the rest goes into the atmosphere. She added that around 100,000 measurements of CO2 have been collecting by OCO-2 on the daily basis over the tropical forest regions.

According to NASA, CO2 concentration has been changing constantly from season to season in the atmosphere of Earth.

The space agency said that since the 1800s, the average concentration of CO2 in the atmosphere has been increasing every year. After the rise of the industrial revolution, the consumption of carbon dioxide in the atmosphere has increased from 595 gigatons to 850 gigatons.

NASA plans to launch its OCO-3 mission next year, whose main focus would be to observe the effect of growing urban population and use the fossil fuels on the climate change.